So far I haven't noticed any changes after listening to it for a while. BTW, the DX90 sounds like a more refine version of the AudioQuest DragonFly, which also uses an unspecified version of the ESS Sabre DAC.

If you are talking rev 1 or 1.1 dfly I thought it was known to run a 9023.

some of my files on the sd card will have artist folder, album folder but then no songs so the dx90 doesn't have anything to play. When I use mp3 tag there are no tags for those folders. How do I get tags if mp3tag cant find them? The tags are on the computer and play fine from there just not on the dx90.

Jim

It sounds like you are experiencing the media scan bug. Check the DX90 bug thread for details or to include your experiences.

I just heard back from the seller and they will replace my unit. I need to send back my defective one to their location in Virginia.

I decided to ask for a full refund since I intended to sell this when I got my unit back from ProStudio Sound and Music. I will report back here as to whether they honor the warranty and refund my full purchase price. They said something about a restocking fee, but they will need to replace my unit with a new one anyways, so it does not seem right to charge me a restocking fee.

I have tested the HE-500 driven just by the DX90. I don’t remember if was Jamato who said an statement similar to that what I’m gonna say.

The HE-500 sounds good just driven by the DX90, mind you, sounds better when they’re amplified with the emotiva mini. By the way my HE-500 didn’t come with a plug 3.5 and an adaptor 6.35, it came with a plug 6.35 so I had to buy an adaptor.

I also have been listening the DX90 with the Etymotic 4PT and with the Westone 4r. I like more the combination of the Etys with the DX90. The Weston sounds really good but I prefer the sound of the Etys.

I have tested the HE-500 driven just by the DX90. I don’t remember if was Jamato who said an statement similar to that what I’m gonna say.

The HE-500 sounds good just driven by the DX90, mind you, sounds better when they’re amplified with the emotiva mini. By the way my HE-500 didn’t come with a plug 3.5 and an adaptor 6.35, it came with a plug 6.35 so I had to buy an adaptor.

I also have been listening the DX90 with the Etymotic 4PT and with the Westone 4r. I like more the combination of the Etys with the DX90. The Weston sounds really good but I prefer the sound of the Etys.

I think it were my findings with the HE-500 you mention. Also the Tzar350 is a good mate to the DX90

mW is power input. V is voltage input. Power depends on two of the three variables(V,I,R), and then there is only voltage dependency for sensitivity. One maybe more efficient than the other, but not necessarily more sensitive while at it.

Ok this is becoming a sound science topic but is a very basic one. V, I, R are all involve but you only need to get 2 values of any combination of the 3 to compute for power. These are not absolute values because there are other factors involve (e.g. cuurent limiter circuit etc) but the headphone sensitivity/efficient spec are nominal values and they are good enough as a general guide.

To make things simple:

96dbSPL/mW headphone definitely will play louder than a 97 dbSPL/V all things equal. If you don't agree the best thing to prove it is get the 2 exact headphones in question K545 and DT880 and see which one sounds louder.